#include<iostream>
#include<stdio.h>
#include<string>
#include<iomanip>
using namespace std;
int main()
{
	char x;
	double a,b;
	cin>>a>>b>>x;
	switch(x)
	{
		case'+':
			x=a+b;
		cout<<setiosflags(ios::fixed)<<setprecision(2)<<a+b<<endl;
		break;
		case'-':
			x=a-b;
			cout<<setiosflags(ios::fixed)<<setprecision(2)<<a-b<<endl;
			break;
		case'*':
			cout<<setiosflags(ios::fixed)<<setprecision(2)<<a*b<<endl;
			break;
		case'/':
			x=a/b;
			cout<<setiosflags(ios::fixed)<<setprecision(2)<<a/b<<endl;
			break;
		default:
			cout<<"输入有误" <<endl;
			break;
			
	}
	return 0;
}